A "purifying" evolution chain?

CurchinThe spiny curse PokemonGhost/WaterRumor has it in ages gone by these Pokemon were used to purify the accursed to the point that the entire species has become tainted

Evolves into LeecherousGhost/Water

And again intoSpectraglobinGhost/Water

But in recent times it has been found the cursed spirits could become unbound again by human intervention

Dawn stone "shedinjas" a ghost type from curchin evolving them into a pure Pokemon and a ghost respectively, which go on to have their own evo and prevo, effectively merging 3 lines.... however you can breed egg moves from one to the other as breeding between all 3 final forms is acceptable

....at least thats the idea the name of this topic gave me

I'd go into more detail but it is just a fakemon... perhaps if I ever get back into poke hacking I'll use it

PS: I think this is the only Pokemon our fearless immortal unaging peterpan hero Ash Ketchum would choose to evolve, as it would be "lifting a curse" and a positive move

PPS: think slowpoke n shelder could do the same thing sorta?

Cool idea, but when I said purifying, I meant it in the type of selection. It's when a trait narrows in on an optimal value from both extremes. ie A pokemon with a long tail, and short tail both evolve into a pokemon with a medium length tail.